DULUTH - Spilling out of a city bus Wednesday morning, a cadre of federal agents and Duluth police officers raced into the Last Place on Earth with guns drawn, ordering everyone face down onto the floor.

"I was terrified to have a gun pointed at my face," said Cynthia Peterson, 20, who had come to the head shop with her fiancé and a friend of his who intended to buy synthetic marijuana sold as "herbal incense."

The raid, the second on the Duluth establishment in less than a year, was part of a nationwide federal crackdown Wednesday on dealers in what health experts consider the latest illegal drug epidemic: man-made chemicals designed to mimic marijuana, ecstasy and other illegal drugs. Sold online and in stores as "incense," "bath salts," "plant food" and other innocuous-sounding products, synthetic or designer drugs have generated thousands of calls to poison control centers and have been linked to more than 20 deaths in the United States, including two in Minnesota.

Michele Leonhart, an administrator with the Drug Enforcement Agency (DEA), scheduled a news briefing for Thursday to announce "Operation Log Jam," a "takedown" of synthetic-drug dealers in 100 cities across the country. Duluth's raid apparently was the only one in Minnesota.

DEA raids also were reported to have occurred Wednesday in New York, Texas, Florida, New Mexico, Arizona, New Hampshire and Pennsylvania. Jeanne Cooney, a spokeswoman for the U.S. attorney's office in Minneapolis, said most of the raids targeted dealers, whereas agents in Duluth only seized evidence.

"We are executing search warrants in connection to an ongoing investigation," Cooney said. "We are not at this time making any arrests or filing charges."

Bruce Bisping, Dml - Star Tribune

Federal agents and local authorities spilled out of a transit bus and went in to the Last Place on Earth head shop in downtown Duluth on Wednesday to execute search warrants.

Minnesota Gov. Mark Dayton, in a ceremony scheduled for Thursday morning, is expected to sign a bill that will make it a felony to sell synthetic drugs. The law takes effect Aug. 1.

Jim Carlson, owner of the Duluth head shop, was on a fishing trip to Alaska on Wednesday, according to his girlfriend and business partner, Lava Haugen.

She said the officers presented a warrant and seized at least $20,000 worth of herbal incense, and files, invoices and other business records as well as a number of guns Carlson kept at the store. Officers also identified and searched customers, arresting at least two for outstanding warrants.

Peterson said those arrested included her fiancé, Phillip White, who was sought by Benton County authorities for allegedly violating terms of probation.

Haugen said police closed the store for at least several hours while conducting the raid.

Minnesota outlawed many of the chemicals in synthetic drugs last year. Carlson, of Superior, Wis., was one of the few dealers in the state who continued to sell them, saying he switched to products with different formulas that might not be covered by the law.

He said in a 2011 interview that his store was on pace to sell $6 million in synthetic marijuana and stimulants that year. Asked Wednesday whether sales had met that expectation, Haugen said: "Yes, sales have been just as good, if not more so."

Duluth police raided Carlson's store in September, seizing what he said was $50,000 worth of herbal incense, thousands of dollars in cash, his computer, cellphone and 31 guns.

No charges were filed after that raid, however. Jon Holets, an assistant St. Louis County attorney, said that's because local authorities learned of the federal investigation and decided to "collaborate" with federal authorities rather than prosecute Carlson under state laws.

Carlson's attorney, Randall Tigue, said that he had yet to see the search warrant for Wednesday's raid but was puzzled about its legal basis because new federal synthetic drug regulations don't take effect until October.

Tigue said he's prepared to fight any charges by arguing that the substances are banned based on how the human brain reacts to them.

"Defining criminality by a reaction within the brain makes it a thought crime, and prosecuting someone for that would violate the First Amendment," Tigue said, adding that if Carlson isn't charged in connection with last year's raid, he might sue for the return of the incense.

"What this raid tells me is that the first raid didn't yield anything they could charge him with," Tigue said.

Haugen, who notified Carlson of the raid, predicted that they'll simply reorder products and restock shelves, as they did after the last raid. "I'm sure we're going to reopen and keep doing what we were doing," she said.

While some customers, including Peterson, said the raid amounted to nothing more than "hassling people," Dean Baltes, owner and publisher of Shel/Don Design & Imaging, a shop next door, said he was thrilled to see it.

For more than a year, Baltes and owners of other nearby businesses have complained that Carlson's synthetic drugs have attracted an unsavory and sometimes strung-out clientele that intimidates and disgusts visitors to Duluth's "Old Downtown."

"My partner, who is a CPA, calculated that it costs us $2,000 a day in walk-in trade," Baltes said as he watched the raid from across the street. "People don't want to deal with the violence, or the vomit in our doorway. I didn't expect this, and I'm extremely glad it's happening. I hope it sticks."